1. Field of the Invention
The present invention relates to a resistance element which is used as a load resistor in a resistance type static random access memory (SRAM) device or the like.
2. Description of the Related Art
A prior art resistance element is formed by a connection layer having a flexing point divided into a high resistance section and a low resistance section. In this case, the high resistance section includes the flexing point. The flexing point is a bending point or turning point of the connection layer and is identified as point 1a. A boundary between the high resistance section and the low resistance section is perpendicular to the connection layer, and another boundary 100c between the high resistance section and the low resistance section is also perpendicular to the connection layer. The resistance value R of the connection layer is substantially determined by the high resistance section. This will be explained later in detail.
In the prior art resistance element, however, the resistance value of the resistance element easily fluctuates due to the manufacturing steps, particularly, the displacement of a photoresist pattern layer for defining the resistance element.
Also, when the prior art resistance element is applied to load resistance of a resistance type SRAM cell, if the resistance value of one of the load resistors is increased and the resistance value of the other is decreased, so that the resistance values of the load resistors are unbalanced, the data retention characteristics are deteriorated. Further, in the SRAM cell, a current always flows through one of the load resistors. Such a current is determined by a smaller one of the resistance values of the load resistors. Also, the larger the above-mentioned current, the greater the power dissipation of the entire SRAM device. Therefore, in order to reduce the power dissipation, the resistance values of the load resistors have to be larger, even if these resistance values of the load resistors are unbalanced. However, if the resistance values of the load resistors is too large, the standby characteristics and the soft error rate by .alpha. rays are deteriorated, and also, the margin of the manufacturing steps is decreased which increases the manufacturing cost.